27" Imac w two apple 27" monitors question

[neverenoughtoys]

I have an 8 year old iMac w two 27" monitors. it seems to me that an application can only be displayed on one monitor. Is there a way to stretch a single application over two of the monitors? (This would allow me to see both monitors at work from home. As it is, I can only see one of my work monitors unless I want to see both work monitors on one monitor at home which is super tiny. The alternative is to keep flipping back and forth from one work monitor to the other) Any suggestions are appreciated. Thank you.

 

[joevt]

Unselect "Displays have separate spaces" in Mission Control preferences panel?

 

[arw]

^^ great hint. Works with RealVNC Viewer. Although fullscreen mode is single-monitor only.
edit: Unfortunately this means the menu bar is only visible on the main screen. But good to know!